What is your favorite Christmas song?

I grew up singing German songs for Christmas in our little Lutheran church and still remember "Kling Glichen" and ending Christmas Eve service with "Stille Nacht". In college I learned a medieval song "Adam Lay Embounded" and my children learned in their school "Bring a Torch Jeannette Isabella". I also like "Coventry Carol" from our time in England, and we decorate our tree by "Once in David's Royal City. I love to hear and sing along to many more. What songs do you enjoy?

Oh Holy Night is my favorite. It brings to mind a church with a steeple set high on a hill that we drove by on the way to my aunt's house every Christmas Eve when I was a kid. There was always snow on the ground.